1. Field of the Invention
The present invention is directed generally to an apparatus and method for inputting data. More particularly, the present invention is directed to an apparatus and method that may be embodied in a relatively small package and still provide a full sized, or larger, input device.
2. Description of the Background
Input devices are used in almost every aspect of everyday life, including computer keyboards and mice, automatic teller machines, vehicle controls, and countless other applications. Input devices, like most things, typically have a number of moving parts. A conventional keyboard, for example, has moveable keys that open and close electrical contacts. Moving parts, unfortunately, are likely to break or malfunction before other components, particularly solid state devices. Such malfunction or breakage is even more likely to occur in conditions that are dirty or dusty. Furthermore, input devices have become a limiting factor in the size of small electronic devices, such as laptop computers and personal organizers. For example, to be efficient a keyboard input device must have keys that are spaced at least as far apart as the size of the user's finger tips. Such a large keyboard has become a limiting factor as electronic devices become smaller.
Some prior art devices have attempted to solve one or more of the above-mentioned problems. For example, touch screens can sense a user touching an image on the monitor. Such devices, however, typically require sensors and other devices in, on, or around the monitor. Furthermore, reducing the size of such an input device is limited to the size of the monitor.
Other prior art devices sense the position of a user's finger using light sensors. Those devices, however, often require light sensors to be located above and perpendicular to the keyboard, or other input device. As a result, they tend to be bulky and are not suited for use in small, hand-held devices.
Other prior art devices sense position of a user's finger with light sensors located on the surface to be monitored. In the case of a keyboard, for example, such devices typically require that sensors be located at the corners or other boundaries of the keyboard. As a result, they are bulky because the sensors must be spread out to be at least the same size as the keyboard. Such a device does not lend itself to use in a small, hand held device or in providing a full sized keyboard, or other input device.
As a result, the need exists for an input device that is large enough to be used efficiently, and which can be contained within a small package, such as an electronic device, like as a laptop computer or a personal organizer. The need also exists for an input device that is not susceptible to failure caused by particulate matter, such as dirt and dust.